Author: Urs Format: MarkdownItexbrushed-up the formatting of this ancient entry
<a href="https://ncatlab.org/nlab/revision/diff/Borchers+property/3">diff</a>, <a href="https://ncatlab.org/nlab/revision/Borchers+property/3">v3</a>, <a href="https://ncatlab.org/nlab/show/Borchers+property">current</a>